The coast's susceptibility to big storms is clearly no secret, but ever wonder what the shoreline looked like 100 years ago? Or about the rate at which sea level is changing? The U.S. Geological Survey released an interactive website last week that will allow Coastians to easily research coastal changes.

The tool, called the USGS Coastal Change Hazards Portal, shows changing sea levels, retreating shorelines and vulnerability to extreme coastal storms. A link to the site can be found at sunherald.com.

USGS research geologist Robert Thieler said a large driver behind the portal, which became available July 16, was to bring the three research themes together into one easy-to-use website. He said the functionality of the site and the value of the information make it a useful tool for the general public as well as city and county officials.

Along the Mississippi Gulf Coast, Thieler said, the portal shows "rather high rates of long-term coastal erosion and shoreline retreat."

"What this shows is there are pieces of coastal real estate that are very dynamic and changing very rapidly and are, in some cases, adjacent to other places that are not changing as rapidly," he said. "Our job as scientists is to use this information to understand why these differences exist and to develop predictive capability for understanding how long into the future this might persist, how the landscape might change and what are the hazards going into the future."

Thieler acknowledged predicting storm vulnerability based on historical data is an inexact science, which is why the USGS uses as much information as is available.

"It's fraught with peril because (a lot can change): The nature of the storms that drive a lot of the rearrangements in the sand and coastal system; how sediment is transferred along the shore; (and) how people manipulate the shoreline after a storm by building back beaches and dunes and things," he said. "These can all contribute to what we would measure at any point in time as a rate of coastal change. Simply taking these kinds of data and multiplying by 10 and then projecting the shoreline can be, in many cases, misleading."

Harrison County Emergency Management Director Rupert Lacy said he has used USGS products and can see the new comprehensive website will come in handy.

"I look at their sites because they do have numerous maps that are out there on their national assessment page," he said. "Any time you talk about water inundation I'm always curious. Besides the miles of coastline, we have the three major rivers.

"We can't get enough information to keep us going."

Thieler said the website will continue to evolve. With any luck, he said, a fourth button will appear on the site by next hurricane season that will show an assessment of the movement probabilities of an incoming storm that is updated in concert with the National Hurricane Center.

"They produce the projections of hurricane intensity and distribution of storm surge and we use that data to generate models for the potential for dune erosion," he said.

As new data is made available, Thieler said, the website will update automatically.

©2014 The Sun Herald (Biloxi, Miss.)